@ArcadeFireTube also pointed out that multi-instrumentalist Richard Reed Parry was recording earlier this month in New Orleans (where Butler and Régine Chassagne live):

Richard was down in New Orleans on Feb 2nd recording with long-time Arcade Fire producer Markus Dravs. Feels like it could very well be connected to this. [Instagram: rrparry] pic.twitter.com/OVQ4ZHDNAo